Braided medical device and method

ABSTRACT

A method for making a neutral hybrid braided structure may involve positioning a first set of wires on a braiding machine in a first set of positions, positioning a second set of wires on the braiding machine in a second set of positions so that the first set of positions and the second set of positions form a neutral hybrid braiding pattern, and braiding the first set of wires and the second set of wires on the braiding machine to form the neutral hybrid braided structure. Each wire in the first set of wires has a first cross-sectional diameter, and each wire in the second set of wires has a second cross-sectional diameter that is smaller than the first cross-sectional diameter.

RELATED APPLICATIONS

The present application claims priority to U.S. Provisional ApplicationNo. 62/988,100, filed on Mar. 11, 2020 and titled, “Braided MedicalDevice and Method,” which is hereby incorporated by reference in itsentirety.

TECHNICAL FIELD

The present application is related to medical devices and methods. Morespecifically, the application is related to braided medical devices andmethods for manufacturing them.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a side view of an embodiment of an expanding medical device inan expanded configuration.

FIG. 2 is a side view of the expanding medical device of FIG. 1 in aconstrained configuration.

FIG. 3A is a side view of an embodiment of a braided wire structure ofthe expanding medical device of FIG. 1 including the neutral hybridbraid pattern.

FIG. 3B is a close-up view of a portion of the braided wire structure ofFIG. 3A.

FIG. 3C is another close-up view of a portion of the braided wirestructure of FIG. 3A.

FIG. 4A is a schematic front view of an embodiment of a wire braidingmachine showing a set-up for a neutral hybrid braid pattern.

FIG. 4B is a schematic side view of a portion of the wire braidingmachine of FIG. 4A.

FIG. 5 is a table illustrating the neutral hybrid braid pattern set-upof FIG. 4A

DETAILED DESCRIPTION

Braided medical devices are used for a number of different applicationsin the body. In certain instances, implantable braided devices are usedin vascular and cardiovascular procedures to prop open a blood vessel,act as a filter for capturing blood clots, occlude a blood vessel,occlude a congenital or structural cardiac defect, act as a supportstructure for an artificial valve, and the like. In some embodiments, abraided device is delivered to its implant location in the body througha catheter in a collapsed, smaller diameter configuration and then,after exiting the catheter, it expands into a larger diameterconfiguration to contact and attach itself to the wall of the bloodvessel or other lumen or defect in which it is being implanted.

Braided devices can be made of multiple wires, including wires made of ashape memory material, such as Nitinol, braided together to form thestructure of the device. Some braided devices use wires that are all thesame material and the same diameter. In other devices, wires withdifferent diameters are used (a process called “hybrid braiding”), tocreate a device. Some reasons for using hybrid braiding include: (a) tocreate a device with a desired overall stiffness (if using all largerwires would be too stiff and using all smaller wires would be tooflexible); (b) to create a device with a desired cross-sectional area(if using all larger wires would be too large and using all smallerwires would be too small); and (c) no single wire size will provide thedesired properties for the given braided device.

Braided devices work well in many applications, but they can sometimescause technical challenges or issues. For example, a hybrid braideddevice can sometimes experience unintentional rotation when movedthrough a lumen of a delivery catheter or other delivery device, due tothe helical nature of the braid or a helical bias created by using wiresof different sizes. This may be problematic if the device being movedthrough the lumen is connected to a delivery member by means of a screwthread. If the threaded connection is a clockwise (CW) direction and thebraided device experiences rotation in the opposite direction whenmoved, then the device could unscrew from the member before it isdelivered to its intended location or deploy in an uncontrolled manner.Conversely, if the threaded connection is a counterclockwise (CCVV)direction and the braided device experiences rotation in the samedirection when moved, then the threaded connection could bind, thuspreventing detachment of the device from the member. The unintentionalrotation may also cause scraping and/or abrasion of the lumen the deviceis being moved through.

In another example, when a hybrid braided device and the device used fordelivering it in the body are permanently connected to one another(glued, welded, brazed, etc.), unintentional rotation of the hybridbraided device relative to the delivery device may cause torque loadsleading to deformation and/or failure of the braided structure and/or ofthe connected delivery member.

An embodiment of a hybrid braided device disclosed within the scope ofthis application includes a first set of wires arranged in a first setof positions and a second set of wires arranged in a second set ofpositions, wherein the first set of wires and the second set of wiresare braided together to form a neutral hybrid braided device. In someembodiments, a diameter of each of the first set of wires is greaterthan a diameter of each of the second set of wires. The hybrid braideddevice may further include a plurality of CW high points where thesecond set of wires cross over the first set of wires in a CW directionand a plurality of CCW high points where the second set of wires crossover the first set of wires in a CCW direction.

A method of braiding the hybrid braided device disclosed within thescope of this application includes positioning the first set of wires ona braiding machine in a first set of positions, positioning a second setof wires on the braiding machine in a second set of positions, andbraiding the first set of wires and the second set of wires on thebraiding machine to form a hybrid braided device having a neutral hybridbraided pattern.

A method of deploying the hybrid braided device disclosed within thescope of this application includes the steps of rotationally couplingthe hybrid braided device to a placement wire, disposing the braidedwire structure within a lumen of a delivery catheter, wherein thebraided wire structure is radially constrained; moving the constraineddevice axially through the inner lumen of the catheter to a targetlocation within the patient; and minimizing or preventing rotation ofthe hybrid braided device relative to the placement wire. The preventionor limiting of the rotation of the hybrid braided device is facilitatedby a plurality of CW high points and a plurality of CCW high points ofthe hybrid braided device to counteract one another during axialmovement.

Embodiments may be understood by reference to the drawings, wherein likeparts are designated by like numerals throughout. It will be readilyunderstood by one of ordinary skill in the art having the benefit ofthis disclosure that the components of the embodiments, as generallydescribed and illustrated in the figures herein, could be arranged anddesigned in a wide variety of different configurations. Thus, thefollowing more detailed description of various embodiments, asrepresented in the figures, is not intended to limit the scope of thedisclosure, but is merely representative of various embodiments. Whilethe various aspects of the embodiments are presented in drawings, thedrawings are not necessarily drawn to scale unless specificallyindicated.

FIG. 1 illustrates an embodiment of an expanding medical device in anexpanded configuration. FIG. 2 illustrates the expanding medical devicein a constrained configuration. FIGS. 3A-3C illustrate an embodiment ofa braided wire structure of the expanding medical device including theneutral hybrid braid pattern. FIGS. 4A, 4B, and 5 illustrate anembodiment of a wire braiding machine showing a set-up for a neutralhybrid braid pattern. In certain views each device may be coupled to, orshown with, additional components not included in every view. Further,in some views only selected components are illustrated, to providedetail into the relationship of the components. Some components may beshown in multiple views, but not discussed in connection with everyview. Disclosure provided in connection with any figure is relevant andapplicable to disclosure provided in connection with any other figure orembodiment.

FIG. 1 depicts an embodiment of an expanding device 100 in an expandedstate. In the embodiment illustrated in FIG. 1, the expanding device 100includes a neutral hybrid braided wire structure 110. The neutral hybridbraided wire structure 110 is composed of three lobes or segments 111with reduced diameter portions 112 disposed between the lobes 111. Inanother embodiment, the neutral hybrid braided wire structure 110 mayinclude a single lobe 111. In yet another embodiment, the neutral hybridbraided wire structure 110 may include two lobes 111 with a reduceddiameter portion 112 disposed between the two lobes 111. Embodimentswith more than three lobes 111, including embodiments with four, five,six, or more lobes 111, are likewise within the scope of thisdisclosure. In the illustrated embodiment, in the expanded state, thelobes 111 have a disc shape. Embodiments where the expanded shape isspherical, ovoid, cylindrical, or any other shape and where the expandedshapes may vary within an expanding device 100 are likewise within thescope of this disclosure.

In the illustrated embodiment, the neutral hybrid braided wire structure110 includes a woven lattice or matrix of wires made from any suitablematerial and may be self-expanding. For example, the material may beNitinol or any other suitable shape memory metal or polymer or anybraidable material. In other embodiments, the woven lattice may beballoon-expandable and may be made from any suitable material, such asstainless steel, titanium, etc. The ends of the wires can be restrainedby clamps 113 disposed at the proximal end 114 and the distal end 115 toprevent fraying of the braid. The neutral hybrid braided wire structure110 can be releasably coupled to a placement wire 130 for deployment.For example, in the illustrated embodiment the neutral hybrid braidedwire structure 110 includes a threaded coupling 116 disposed at theproximal end 114 that can be threadingly coupled to a threaded coupling131 of the placement wire 130. When deployed, the neutral hybrid braidedwire structure 110 can be rotationally held in place relative to theplacement wire 130 when the neutral hybrid braided wire structure 110engages with the vessel wall and the placement wire 130 can be rotatedto release the placement wire 130 from the neutral hybrid braided wirestructure 110. Other mechanisms for release and deployment are alsowithin the scope of this disclosure including, hooks, collets, loops,snares, and so forth.

FIG. 2 illustrates the expanding device 100 in a radially collapsed orconstrained or low-profile state. As illustrated, the expanding device100 is disposed within a lumen 171 of a delivery device 170 (e.g.,delivery catheter). The neutral hybrid braided wire structure 110 isradially compressed and constrained by a wall 172 of the delivery device170 wherein the lobes 111 are in contact with the wall 172 resulting infrictional resistance as the neutral hybrid braided wire structure 110is pushed through the delivery device 170. In the constrained state, theneutral hybrid braided wire structure 110 is axially lengthened relativeto the length of the neutral hybrid braided wire structure 110 in theexpanded state, as shown in FIG. 1.

FIGS. 3A-3C illustrate a neutral hybrid braided wire structure 210. Asillustrated, the neutral hybrid braided wire structure 210 includeswires 230 braided together in a neutral hybrid braid pattern. The wires230 can be formed from any suitable material. For example, in anembodiment, the wires 230 are formed from a shape memory alloy, such asnickel-titanium alloy. In some embodiments, the material is Nitinol. Inanother embodiment, the wires 230 are formed from any one of stainlesssteel and titanium. Other suitable materials are contemplated. Adiameter of the wires 130 can range from about 0.0005 inches to about0.010 inches. In the embodiment disclosed by this disclosure, the wiresinclude a combination of large wires 231 and small wires 232. A diameterof the large wires 231 may range from about 0.0005 inches to about 0.010inches and a diameter of the small wires 232 may range from about 0.0005inches to about 0.008 inches. When a combination of large wires 231 andsmall wires 232 are braided together, various physical characteristicsof the neutral hybrid braided wire structure 110 may be provided. Thephysical characteristics can include stiffness, flexibility,compressibility, radial expansion, profile, diameter, etc. For example,the stiffness of the neutral hybrid braided wire structure 210 is higherwhen a wire braid includes both large wires 231 and small wires 232 whencompared to a braided wire structure composed strictly of small wires.

In the illustrated embodiment, the neutral hybrid braided wire structure210 includes localized areas where pairs of large wires 231 a, 231 b, asshown in FIG. 3B, and pairs of small wires 232 a, 232 b, as shown inFIG. 3C, travel in both the CW and CCW directions. There are twoCW-travelling large wire pairs and two CCW-travelling large wire pairsand two CW-travelling small wire pairs and two CCW-travelling small wirepairs. The wires 230 are braided in an over-under-over pattern. Forexample, a first wire is braided over a second wire travelingperpendicularly to the first wire, under a third wire traveling parallelto the second wire, and over a fourth wire traveling parallel to thethird wire. In other embodiments, the wires 230 may be braided in anysuitable pattern. For example, the wires 230 may be braided in an overtwo-under one-over two pattern.

As illustrated, the large wires 231 and the small wires 232 travel inboth a CW direction and a CCW direction. The small wires 232 overlap theperpendicularly traveling large wires 231 in the CCW direction and inthe CW direction to form CCW high points 233 and CW high points 234.When the neutral hybrid braided wire structure 210 is constrained withina lumen of a delivery catheter, wherein the CCW high points 233 and theCW high points 234 engage with a wall of the lumen, and is either pulledproximally (toward the user) or pushed distally (away from the user)through the lumen of the delivery catheter, a rotation of the neutralhybrid braided wire structure 210 will be neutral. In other words, theCCW high points 233 and CW high points 234 will counteract each other toresist or prevent the neutral hybrid braided wire structure 210 fromrotating either CW or CCW. This prevents or minimizes the neutral hybridbraided wire structure 210 from either inadvertently detaching from aplacement wire within the delivery catheter or tightening onto theplacement wire to prevent intended rotational detachment of the neutralhybrid braided wire structure 210 from the placement wire within a bloodvessel.

The neutral hybrid braided wire structure 210 can be formed by a wirebraiding machine. FIG. 4A illustrates a partial front schematic view ofa 144 carrier wire braiding machine 300. In other embodiments, the wirebraiding machine 300 may be a 32 carrier, 96 carrier, or any number ofcarries wire braiding machine. The wire braiding machine 300 is shown ina “Half Load” configuration, where only 72 of the possible 144 wirecarriers 310 are present on the wire braiding machine 300. Thirty-six ofthe wire carriers 310 are configured to travel CW around the wirebraiding machine 300, and the other 36 wire carriers 310 are configuredto travel CCW around the wire braiding machine 300. The wire carriers310 are selectively coupled to horn gears 320, as shown in FIG. 4B. Thehorn gears 320 rotate about their own central axis and pass each wirecarrier 310 from one horn gear 320 to an adjacent horn gear 320. Arotation direction of a first horn gear 320 is opposite to a rotationdirection of an adjacent second horn gear 320 and so on, as shown by thearrows of FIG. 4B. In other words, the first horn gear 320 may rotate CWand the immediate adjacent second horn gear 320 may rotate CCW. Notches321 in the horn gears 320 are configured to hold the wire carriers 310until they are passed to the next horn gear 320. Each wire carrier 310holds a single wire spool (not shown). The wire carriers 310 are loadedwith wires 330 in a specific order to achieve the neutral braided wirepattern. The wires 330 all converge at a central point onto a mandrel340 to form a neutral hybrid braid 350 from which a neutral hybridbraided wire structure is formed.

Each wire 330 makes 360-degree rotations around the mandrel 340. Alength of the neutral hybrid braid 350 produced on each mandrel 340 canbe multiple feet, meaning that each wire 330 makes multiple 360-degreerotations around the mandrel 340. The amount of the neutral hybrid braid350 required to produce an expanding device may be a fraction of what isproduced on each mandrel 340, so the braiding process can be a bulkproduction process.

FIG. 4A illustrates a set-up of the wire braiding machine 300 to formthe neutral hybrid braid 350 including the neutral hybrid braid patternaccording to one embodiment within the scope of this disclosure. Theset-up of the braiding machine 300 begins with loading a large wirespool onto the CCW direction travelling carrier #1. Then, another largewire spool is loaded onto the CW direction travelling carrier #2. Next,three small wire spools are loaded onto the next three carriers (#4, #5,#6). The localized groupings of small 332 and large wires 331 arearranged per the table of FIG. 5, which states the location, size, anddirection for each of the 72 wires 330. The wire loading processcontinues until a total of 36 small wire spools and 36 large wire spoolsare loaded onto the carriers 310, with an equal amount of large andsmall wire spools travelling in both the CW and CCW directions.

The set-up of the braiding machine 300 for the neutral hybrid braidpattern is symmetrical, even with the inclusion of localized groupingsof large and small wires spools. When a straight line is drawn from anycarrier 310 through the center of the braiding machine 300, it willconnect to another carrier 310 that has the same wire size spool and istravelling in the same direction. For example, carrier #18 has a largewire spool, carrier #54 has a large wire spool, and both are travellingCW, as shown in FIG. 4A. Therefore, carrier #18 is the 180-degree mirrorimage of carrier #54 about the line A-B. The symmetry or mirroringapplies to all carriers 310 on the braiding machine 300.

Any methods disclosed herein comprise one or more steps or actions forperforming the described method. The method steps and/or actions may beinterchanged with one another. In other words, unless a specific orderof steps or actions is required for proper operation of the embodiment,the order and/or use of specific steps and/or actions may be modified.For example, a method of deploying an expanding medical device mayinclude one or more of the following steps: rotationally coupling abraided wire structure to a placement wire, wherein the braided wirestructure comprises: a plurality of CW high points and a plurality ofCCW high points; disposing the braided wire structure within a lumen ofa delivery catheter, wherein the braided wire structure is radiallyconstrained; moving the constrained device axially through the innerlumen of the catheter to a target location within the patient; andpreventing or limiting rotation of the braided wire structure relativeto the placement wire. Other steps are also contemplated.

Reference throughout this specification to “an embodiment” or “theembodiment” means that a particular feature, structure, orcharacteristic described in connection with that embodiment is includedin at least one embodiment. Thus, the quoted phrases, or variationsthereof, as recited throughout this specification are not necessarilyall referring to the same embodiment.

Similarly, in the above description of embodiments, various features aresometimes grouped together in a single embodiment, figure, ordescription thereof for the purpose of streamlining the disclosure. Thismethod of disclosure, however, is not to be interpreted as reflecting anintention that any claim requires more features than those expresslyrecited in that claim. Rather, as the following claims reflect,inventive aspects lie in a combination of fewer than all features of anysingle foregoing disclosed embodiment.

The phrase “coupled to” refers to any form of interaction between two ormore entities, including mechanical, electrical, magnetic,electromagnetic, fluid, and thermal interaction. Two components may becoupled to each other even though they are not in direct contact witheach other. For example, two components may be coupled to each otherthrough an intermediate component.

The directional terms “distal” and “proximal” are given their ordinarymeaning in the art. That is, the distal end of a medical device meansthe end of the device furthest from the practitioner during use. Theproximal end refers to the opposite end, or the end nearest to thepractitioner during use. As specifically applied to an expanding medicaldevice of this disclosure, the proximal end of the device refers to theend nearest to the practitioner and the distal end refers to theopposite end, the end furthest from the practitioner.

References to approximations are made throughout this specification,such as by use of the term “about.” For each such reference, it is to beunderstood that, in some embodiments, the value, feature, orcharacteristic may be specified without approximation. For example,where the qualifier such as “about” is used, these terms include withintheir scope the qualified words in the absence of their qualifiers.

The terms “a” and “an” can be described as one, but not limited to one.For example, although the disclosure may recite a braided structurehaving “a wire,” the disclosure also contemplates the braided structurehaving two or more wires.

Unless otherwise stated, all ranges include both endpoints and allnumbers between the endpoints.

Recitation in the claims of the term “first” with respect to a featureor element does not necessarily imply the existence of a second oradditional such feature or element.

The claims following this written disclosure are hereby expresslyincorporated into the present written disclosure, with each claimstanding on its own as a separate embodiment. This disclosure includesall permutations of the independent claims with their dependent claims.Moreover, additional embodiments capable of derivation from theindependent and dependent claims that follow are also expresslyincorporated into the present written description.

Without further elaboration, it is believed that one skilled in the artcan use the preceding description to utilize the invention to itsfullest extent. The claims and embodiments disclosed herein are to beconstrued as merely illustrative and exemplary, and not a limitation ofthe scope of the present disclosure in any way. It will be apparent tothose having ordinary skill in the art, with the aid of the presentdisclosure, that changes may be made to the details of theabove-described embodiments without departing from the underlyingprinciples of the disclosure herein. In other words, variousmodifications and improvements of the embodiments specifically disclosedin the description above are within the scope of the appended claims.Moreover, the order of the steps or actions of the methods disclosedherein may be changed by those skilled in the art without departing fromthe scope of the present disclosure. In other words, unless a specificorder of steps or actions is required for proper operation of theembodiment, the order or use of specific steps or actions may bemodified. The scope of the invention is therefore defined by thefollowing claims and their equivalents.

1. A method for making a neutral hybrid braided structure, comprising:positioning a first set of wires on a braiding machine in a first set ofpositions; positioning a second set of wires on the braiding machine ina second set of positions, wherein each wire in the first set of wireshas a first cross-sectional diameter, and each wire in the second set ofwires has a second cross-sectional diameter that is smaller than thefirst cross-sectional diameter; and braiding the first set of wires andthe second set of wires on the braiding machine to form the neutralhybrid braided pattern.
 2. The method of claim 1, wherein the neutralhybrid braided pattern comprises each of the first set of wires beingpositioned immediately adjacent at least one other wire of the first setof wires, and each of the second set of wires being positionedimmediately adjacent at least one other wire of the second set of wires.3. The method of claim 2, wherein the neutral hybrid braided patternfurther comprises four locations around a diameter of the braidingmachine at which three of the second set of wires are positionedconsecutively.
 4. The method of claim 2, wherein the neutral hybridbraided pattern further comprises two locations around the diameter ofthe braiding machine at which four of the first set of wires arepositioned consecutively.
 5. The method of claim 1, wherein each of thewires of the first set of wires and the second set of wires is made of ashape memory material.
 6. The method of claim 5, wherein the shapememory material comprises Nitinol.
 7. The method of claim 1, wherein theneutral hybrid braided pattern further comprises: a plurality of CW highpoints, wherein the second set of wires cross over the first set ofwires in a CW direction; and a plurality of CCW high points, wherein thesecond set of wires cross over the first set of wires in a CCWdirection.
 8. A neutral hybrid braided structure, comprising: a firstset of wires arranged in a first set of positions; a second set of wiresarranged in a second set of positions, wherein the first set wires andthe second set of wires are braided together to form the neutral hybridbraided structure, wherein each wire in the first set of wires has afirst cross-sectional diameter, and wherein each wire in the second setof wires has a second cross-sectional diameter that is smaller than thefirst cross-sectional diameter; and wherein the first set of positionsand the second set of positions form a neutral hybrid braid pattern. 9.The braided structure of claim 8, wherein each of the first set of wiresis positioned immediately adjacent at least one other wire of the firstset of wires, and each of the second set of wires is positionedimmediately adjacent at least one other wire of the second set of wires.10. The braided structure of claim 9, wherein at four locations around adiameter of the braided structure at least three of the second set ofwires are positioned consecutively.
 11. The braided structure of claim9, wherein at two locations around the diameter of the braided structureat least four of the first set of wires are positioned consecutively.12. The braided structure of claim 8, wherein each of the wires of thefirst set of wires and the second set of wires is made of a shape memorymaterial.
 13. The braided structure of claim 12, wherein the shapememory material comprises Nitinol.
 14. The braided structure of claim 8,further comprising: a plurality of CW high points, wherein the secondset of wires cross over the first set of wires in a CW direction; and aplurality of CCW high points, wherein the second set of wires cross overthe first set of wires in a CCW direction.
 15. A method of deploying anexpanding medical device, comprising: rotationally coupling a neutralhybrid braided wire structure to a placement wire, wherein the neutralhybrid braided wire structure comprises: a plurality of CW high points;and a plurality of CCW high points; disposing the neutral hybrid braidedwire structure within a lumen of a delivery catheter, wherein thebraided wire structure is radially constrained; moving the constraineddevice axially through the inner lumen of the catheter to a targetlocation within the patient; and limiting rotation of the neutral hybridbraided wire structure relative to the placement wire.
 16. The method ofclaim 15, wherein axially displacing the neutral hybrid braided wirestructure comprises contacting a wall of the lumen with the plurality ofCW high points, wherein the neutral hybrid braided wire structure isprevented from CCW rotation relative to the placement wire.
 17. Themethod of claim 15, wherein axially displacing the neutral hybridbraided wire structure comprises contacting a wall of the lumen with theplurality of CCW high points, wherein the neutral hybrid braided wirestructure is prevented from CW rotation relative to the placement wire.18. The method of claim 15, further comprising: deploying the neutralhybrid braided wire structure from the delivery catheter into a bloodvessel; radially expanding the neutral hybrid braided wire structurewithin the blood vessel; and rotationally detaching the neutral hybridbraided wire structure from the placement wire.